Format: ORAL

Imke Schmitt1,2

1 Senckenberg Biodiversity and Climate Research Centre, Frankfurt, Germany 2 Goethe University, Frankfurt, Germany

Many species of lichen-forming fungi have wide geographic ranges, and can occur in more than one biome. These species have evolved broad ecological tolerances to cope with different climatic conditions. Here we ask, how climate affects genome architecture and variation in populations of lichenized fungi. We study populations of different species of the rock-inhabiting genus Umbilicaria, collected along elevation gradients. The gradients are located in Europe and North America, and span different climate zones, e.g. the Mediterranean and cold temperate zone. In my talk I will summarize research in my group over the past few years, which overall has shown that there is substantial and abrupt genome-wide divergence between high elevation and low elevation population groups, largely corresponding to biome borders. I will report on fungal genes and genomic features affected by climate, and differences in genomic differentiation of sexually and asexually reproducing species. Furthermore, I will discuss the symbiotic green algae associating with Umbilicaria (Trebouxia spp.), which show community turnovers along elevation, and preferred altitudinal distributions, suggesting that environmental filtering is one driver of symbiont distribution. All in all, our findings contribute to piecing together the complex picture of environmental adaptation in the lichen symbiosis.